It’s perfectly reasonable to suspect that only certain bulbs are dimmable, especially considering all the <a title="Incandescent Bulb Ban" href="http://www.atgstores.com/ourblog/post.aspx?title=Update-Incandescent-Light-Bulb-Ban-of-2014" target="_blank">changes we’re seeing in the light bulb industry</a> these days, but then it’s also possible one might assume the dimmer switch is the variable in the equation.</br></br>So, which is it? Are we buying dimmer switches to match to certain bulbs, or are we buying certain bulbs that can be dimmed?</br></br><strong>Dimmable vs. Non-Dimmable Light Bulbs</strong></br></br>Generally speaking, all common household bulbs (<a title="Incandescent Light Bulbs" href="http://www.atgstores.com/incandescent-bulbs_36.html" target="_blank">incandescent</a>, <a title="Halogen Light Bulbs" href="http://www.atgstores.com/halogen-bulbs_38.html" target="_blank">halogen</a>, <a title="Fluorescent Light Bulbs" href="http://www.atgstores.com/fluorescent-light-bulbs_37.html" target="_blank">CFL</a> and <a title="LED Light Bulbs" href="http://www.atgstores.com/led-light-bulbs_1527.html" target="_blank">LED</a>) are dimmable; however, some of them are made to <em>not be</em> dimmable. Now, why would they even make those, you ask?</br></br>That’s a good question. And, there are a couple different answers; one based in science, and the other in aesthetics and/or functionality.</br></br>Functionally, one can imagine a situation wherein multiple fixtures are on a dimmer, but for whatever reason you’d like X fixture to remain undimmed. For example, let’s say your overhead driveway light is on the same switch as your porch lights and you’d like the driveway light to not dim along with the porch lights – you can just use a non-dimmable bulb.</br></br>The science-y answer has to do with the way dimmers work …</br></br><strong>How Dimmer Switches Work</strong></br></br>As a stripped-down explanation, dimmers work by rapidly shutting off power to the bulb. This creates a flicker effect that, to the human eye, makes it appear as if the bulb is dimmed. This has to do with interrupting the alternating current that flows through your house’s electrical system and … well, is kind of boring unless you’re an electrician.</br></br>Now, the issue with that is that some types of bulbs – primarily CFLs – don’t respond well to fluctuations in voltage. There are CFLs that can be dimmed, but you’ll find people on both sides of the fence willing to argue the merits of those bulbs.</br></br><strong>Calculating Light Source “Load Type”</strong></br></br>Any dimmer you choose will only be able to handle a certain “wattage load” from the bulbs you’re dimming. The dimmer will indicate its wattage load on the packaging, which must be high enough to accommodate the combined wattage of the lights you’re dimming.</br></br>This is typically not a problem. It’s rare in residential lighting to have a need to dim more bulbs than the average dimmer can handle.</br></br><strong>Dimmer Type & Style</strong></br></br>There are several different kinds of dimmers, and they can differ in wattage load and wall-switch functionality. You’ll also find some that are designed for specific <a title="Light Bulbs" href="http://www.atgstores.com/light-bulbs_7.html?linkloc=tn" target="_blank">types of bulbs</a> (usually LEDs and CFLs), and these will be clearly marked as specialty dimmers.</br></br>The need for different kinds of dimmers, again, goes back to the differing bulb types and what happens to those bulbs when you expose them to fluctuating current. That said, wattage load and the kind of switch function you prefer (sliding, toggle, rotating, etc.) are the key differences in most cases.</br></br><strong>Dimmable Lighting Products</strong></br></br>Finally, it’s important to make the distinction between dimmer switches and <em>products</em> with dimmer switches. As you know, some lighting fixtures (<a title="Wall Sconces" href="http://www.atgstores.com/wall-sconces_92.html?linkloc=tn" target="_blank">wall sconces</a>, <a title="Lamps" href="http://www.atgstores.com/lamps_869.html?linkloc=tn" target="_blank">lamps</a>, <a title="Fans" href="http://www.atgstores.com/fans_15.html?linkloc=tn" target="_blank">fans</a>, etc.) are dimmable at the source and don’t need a dimmer switch at the wall.</br></br>And, if you don’t want to deal with switch installation these might be the way to go.